Drill



H. BERNAY.

DRILL. APPLICATION FILED MAILZI, I919.

Patented Aug. 23, 1921.

HENRI BERNAY, OF SAN FRANCISCO, CALIFORNIA, ASSIGNDR, BY MESNE ASSIGN- MENTS, T0 FRED W. THU'RSTON, OF SAN FRANCISCO, CALIFORNIA.

DRILL.

Specification of Letters Patent.

Patented Aug. 28., 1921.

Application filed March 21, 1919. Serial No. 284,181.

T 0 all whom it may concern:

Be it known that l, HENRI BERNAY, a citizen of the United States, residing in the city and county of San Francisco, and State of California, have invented a new and useful Improvement in a Drill, of which the following is a specification.

My invention relates to improvements in drills for drilling rock and the like wherein a cruciform bit operates in conjunction with a lateral retaining pin; and the objects of my invention are:

First, to provide an improved drill for drilling rock and the like having a detachable bit;

Second, to provide improved and simplified means for detachably mounting and retaining a detachable bit within a chuck;

Third, to provide an improved rock drill having a detachable cruciform bit of simple and effective construction which may be readily and easily renewed;

Fourth, to provide an improved device of the character described possessing simplicity and cheapness of construction and a maximum'efficiency;

Fifth, to provide an improved and simplified construction for rock drills and the like wherein the bits may be easily and readily removed and replaced by new and sharpened bits when the old bits have been rendered inoperative through usage or from any other purpose; and a Sixth, to provide a barely discernible taper for retaining pin and means for preventing disclosed in the drawings forming a part of the present specification, wherein like characters of reference are used to designate similar parts throughout the said specification and drawings, and in which:

Figure 1 is a front elevation of my improved bit;

Fig. 2 is a plan view of Fig. 1;

Fig. 8 is a vertical sectional view;

Fig. 4 is a side elevation of Fig. 1.

Referring to the drawings the numeral 1 is used to designate a chuck having a central bore 2 provided with an enlarged portion 3 to receive a shank not shown.

The chuck 1 is also provided with longitudinally disposed slots 4 arranged at right intersecting the slots 4 of said chuck 1 and provided with a reduced portion at one end of said aperture 6, the purpose of which will hereinafter be more fully described.

A. bit 8, cruciform in shape, and wider at one end, is provided with cutting edges 9 on at least one end thereof as disclosed in Fig. 1 ofthe drawings. The bit 8 is near its inner end provided with a centrally disposed locking aperture 11 arranged diagonally to the blades of the bit 8 and passing through the junction of said blades.

The diagonal locking aperture 11 is arranged to register with the aperture 6 in the chuck 1 when the bit 8 is mounted within the slots 4.

A tapered pin 12 is mounted within the registering apertures 6 and 11 of the chuck 1 and bit 8 respectively, said pin being provided with a reduced portion 14 to engage the reduced portion 7 of the aperture 6 whereby said tapered pin 12 may be inserted within said registered apertures from the proper endv only to prevent jamming said pin when only a slight and barely discernible taper is provided.

In operation the bit 8 is seated within the slots 4 of the chuck 1 to register the locking aperture 11 therein with the lateral tapered aperture 6 of the chuck 1 and the pin 12 is inserted within said registered apertures.

The wider end of the bit 8, provided with the cutting edges 9,. is slightly wider than the diameter of the chuck 1 so that said cutting edges will drill a hole in rock or the like greater than the diameter of said chuck whereby successive drills of constantly decreasing sizes may be used to replace a worn bit without bindingin the last portion of the hole bored by a dulled bit just previous to its removal.

The tapered pin is provided with a reduced portion 14 to engage the reduced portion 7 of the aperture 6 or the aperture 6 in order to prevent inaccurate insertion of the tapered pin and jamming or the pin in consequence of such inaccurate insertion as the provision of said reduced portion 7 of the aperture 6 or the aperture 6 will prevent insertion of the pin 12 from that end.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A drill comprising a chuck having a central aperture and lateral slots arranged at right angles to each other and also having a lateral aperture reduced at one end thereof; a cruciform bit detachably mounted within the slots and having one end wider than the other and cutting edges on said wider end, and likewise provided with a diagonal aperture arranged to register with the aperture within the chuck; and a pin mounted within said aperture and having a reduced portion to engage the reduced portion of the aperture whereby said pin may be inserted within said aperture from one end only,

2. A drill comprising a chuck having a central aperture and lateral slots arranged at right angles to each other and likewise provided with a tapered aperture having a reduced end; a cruciform bit mounted within the slots and having one end wider than the other end thereof said wider end being provided with cutting edges, and said bit belng likewise provided with a diagonal aperture arranged to register with the aperture in the chuck; and a tapered pin mounted within the aperture of the'bit and the tapered aperture within the chuck and having a reduced portion to engage the reduced portion of the tapered aperture of the chuck.

3. A drill comprising a chuck having lateral slots therein and likewise provided with a tapering aperture arranged diagonally to and intersecting the slots and having a reduced portion at one end; a cruciform bit mounted within the slots and having a centrally disposed aperture arranged to register with the diagonal aperture in the chuck; and a pin mounted within the registering apertures and provided with a reduced portion to engage the reduced portion of the aperture in the chuck whereby said pin may be inserted from one end onlyof the tapered aperture.

In witness whereof I hereunto set my signature.

HENRI BERNAY. 

